The present invention relates to a depth signal generation apparatus, a pseudo stereo image signal generation apparatus, a depth signal generation method, a pseudo stereo image signal generation method, a computer-readable recording medium recording a depth signal generation program therein, and a computer-readable recording medium recording a pseudo stereo image signal generation program therein, for generating a depth signal from a usual still image or moving image, that is, an image (non-stereo image) which is not provided with depth information explicitly, or implicitly as in a stereo image, providing processing based on this depth information for the non-stereo image, and thereby generating and outputting a pseudo stereo image which provides a stereoscopic effect.
In a stereo display system, for enabling the non-stereo image to be viewed in pseudo stereo image viewing, there is performed processing of generating a pseudo stereo image from a usual still image or moving image, that is, an image (non-stereo image) which is not provided with depth information for expressing a stereo object explicitly, or implicitly as in a stereo image.
As an example of such a technique, there is known an approach of generating a stereo image on the basis of a depth signal generated by superimposing a depth model which combines a plurality of basic depth models according to a feature of an input non-stereo image, on an R signal of a non-stereo image, for example (refer to Patent Document 1: Japanese Patent No. 4214529).
In the pseudo stereo image generation technique as represented by patent document 1, when estimation error is caused in the depth signal, there is a possibility that a stereo image generated according to the estimated depth signal provides uncomfortable feeling. Meanwhile, this uncomfortable feeling could be reduced by the use of a weak gain in the depth signal estimation when the stereo image is generated. In such a case, however, the gain becomes weak also in an image area where the estimation error is not caused in the depth signal, and sometimes the whole image provides a poor stereoscopic effect.